Bucket Cylinder Seal Kit 215-9986 for CAT 320C Excavator | Hydraulic Repair Set 2159986

Restore Digging Power & Stop Hydraulic Oil Leaks

When internal seals degrade inside the bucket cylinder, hydraulic fluid bypasses the piston head—causing slow cycle times, loss of breakout force, and uncommanded bucket drift during heavy digging.

This heavy-duty 215-9986 cylinder seal kit restores original operating pressure and structural holding force for Caterpillar 320C hydraulic excavators. Every seal, buffer ring, and wiper in this pack is matched to original factory dimensions for a zero-leak, drop-in field overhaul.

Material & Performance Engineering

• High-Pressure Rod & Piston Seals: Precision-molded Polyurethane (PU) resists extrusion, dynamic distortion, and pressure spikes up to 35 MPa during severe earthmoving operations.

• Secondary Static Seals & O-Rings: Premium Nitrile Rubber (NBR 70°/80° Durometer) maintains elastic sealing memory across broad thermal cycles while standing up to mineral-based hydraulic oils.

• Aggressive Wiper Ring: Sweeps away abrasive silica sand, mud, and slurry from the chrome piston rod, preventing internal barrel scoring and oil contamination.

• PTFE Back-Up Rings: Reinforced anti-extrusion rings provide extra stability under continuous high-temperature hydraulic loads.

Target Equipment & Component Compatibility

• Machine Model: CAT 320C Excavator

• Target Component: Bucket Cylinder Assembly

• Part Number Cross-Reference: 215-9986 / 2159986 / 215 9986

Technical Specifications

• Kit Type: Hydraulic Bucket Cylinder Rebuild / Packing Set

• Primary Materials: Polyurethane (PU), Nitrile Rubber (NBR), Industrial PTFE

• Operating Temperature Range: -30°C to 110°C (-22°F to 230°F)

• Fluid Compatibility: Mineral hydraulic fluids, standard ISO VG 32/46/68 oils

• Installation Target: Direct replacement drop-in fit for field maintenance or shop overhauls

Fitment Verification Notice

Caterpillar 320C excavators may feature different cylinder barrel configurations depending on equipment serial prefixes and regional specs. Before ordering, verify the stamped part number on your cylinder gland or cross-reference 215-9986 / 2159986 in your CAT parts manual.